25L Waterproof Duffel Backpack with 3-Way Carry — SL-C261
Product Description
Product Detail
Page title: 25L Duffel Backpack — TPU Welded, 3-Way Carry | OEM
Meta description: 25L TPU duffel backpack, welded seams, airtight main zip, IPX7. Carries as duffel, shoulder bag or backpack. MOQ 300, samples 7–15 days, custom logo.
At a Glance
| Model | SL-C261 |
| Capacity | 25 L |
| Dimensions | 48 × 26 × 26 cm |
| Weight | 1.35 kg with shoulder straps |
| Material | TPU-laminated 420D nylon |
| Construction | High-frequency welded seams |
| Closure | Airtight main zip under fold-over collar |
| Water rating | IPX7 main compartment |
| Carry modes | Duffel / shoulder bag / backpack |
| Colours | Blue two-tone, yellow/sky blue, black, gray, green, orange |
| MOQ | 300 pcs |
| Lead time | 30–35 days after sample approval |
Product Description
SL-C261 is a 25 L cylindrical duffel measuring 48 × 26 × 26 cm and weighing 1.35 kg with the shoulder straps fitted. The body is TPU-laminated 420D nylon with all structural seams high-frequency welded. The main compartment opens through an airtight zip running along the top of the bag; above it, an extended collar can be left flat or folded once or twice and held down by the carry handles for extra protection in spray. On the front panel sits a welded zip pocket for small items, with a daisy-chain webbing strip and two D-rings above it for clipping gear. Two cross straps with side-release buckles run over the body and double as compression straps. Each end cap carries welded webbing loops and a D-ring, and one end has a rubber-sleeved grab handle for lifting the bag out of a hatch or a car boot. The bag is carried three ways: by padded twin handles, by a removable padded shoulder strap on snap hooks, or as a backpack using the detachable padded shoulder straps, which clip onto a fixed padded back panel on the rear of the body.
Closure and Water Behaviour
The main opening is an airtight zip, not a coil zip with a rain flap, so the main compartment stays dry without relying on a roll-top. The fold-over collar is a second line of defence rather than the primary seal: in heavy spray or when the bag sits in the bilge of a boat, folding the collar over and clipping the handles across it keeps grit and standing water away from the zip teeth, which is what extends the service life of any airtight zip. With the zip closed, the main compartment is rated IPX7, verified by full water-immersion test, 2+ hours. The front pocket uses a water-resistant zip and should be treated as splash-proof storage for items that tolerate a little moisture — keys, snacks, sunscreen — not phones or documents.
All seams on the body are high-frequency welded, and the webbing loops, D-ring tabs and shoulder strap anchor points are welded on as separate reinforcing patches rather than stitched through the waterproof wall. That is the detail that keeps a bag with this many attachment points waterproof: every needle hole through the main wall is a potential leak, and on SL-C261 there are none.
Three Ways to Carry
As a duffel, the twin handles close together under a padded wrap and the bag is carried by hand like a gym or weekend bag. As a shoulder bag, the removable strap clips to the end-cap D-rings with metal snap hooks and has a wide padded shoulder section, which suits walking from a car park to a dock or a boat ramp. As a backpack, the detachable padded shoulder straps clip onto anchor points on the fixed back panel, and the bag sits upright along the spine — the mode to use for longer walks, portages or carrying across a beach.
The padded back panel is built into the rear of the bag and stays in place in every carry mode. It keeps the load off the spine when worn as a backpack, and in duffel mode it gives the bag a flat, stable face to rest on in a boot or on a deck. The shoulder straps unclip when not needed, so they do not snag when the bag is stowed in a hatch or under a seat.
Engineering Specifications
| Model | SL-C261 |
| Capacity | 25 L |
| Dimensions | 48 × 26 × 26 cm |
| Weight | 1.35 kg with shoulder straps; 1.20 kg without |
| Load rating | 15 kg |
| Water rating | IPX7 main compartment; front pocket splash-proof |
| Seam construction | High-frequency welded body seams |
| Attachment points | Welded reinforcing patches, no stitching through main wall |
Material Specifications
| Body | TPU-laminated 420D nylon |
| Main zip | Airtight zip |
| Pocket zip | Water-resistant coil zip |
| Webbing | 25 mm and 38 mm polyester |
| Buckles | Side-release, acetal |
| D-rings | Metal and moulded plastic |
| Shoulder strap hooks | Metal snap hooks |
| Padding | EVA foam, mesh- or TPU-faced |
Functional Specifications
| Main compartment | Single open compartment, airtight zip |
| Collar | Fold-over, secured by carry handles |
| External storage | Front welded zip pocket |
| Gear attachment | Daisy chain, D-rings, end-cap loops |
| Compression | Two cross straps with side-release buckles |
| Hand carry | Twin handles with padded wrap; rubber-sleeved end handle |
| Shoulder carry | Removable padded strap |
| Backpack carry | Detachable padded shoulder straps on fixed padded back panel |
| Storage | Folds soft when empty |
Customization and OEM
| MOQ | 300 pcs per colour |
| Capacity | 25 L standard; 35 / 45 / 60 L on request |
| Colour | Single colour or two-tone, Pantone matched |
| Logo | Screen print, heat transfer, welded patch, woven label, embroidery on straps and pads |
| Fabric | TPU on 420D / 840D nylon, PVC tarpaulin, GRS recycled base |
| Closure | Airtight zip or roll-top only |
| Harness | Standard or ventilated mesh shoulder straps; back panel padding thickness adjustable |
| Sample | 7–15 days |
Packaging Specifications
| Unit pack | PE polybag with suffocation warning, shoulder straps packed inside |
| Carton quantity | 10 pcs per export carton |
| Labelling | Barcode, SKU, country of origin as specified |
| Options | Hangtag, colour box, retail header |
Recommended Use
Sailing and boating day kit, kayak and SUP trips where the bag rides on deck, weekend travel, beach days, fishing trips, and car camping. The main compartment is suitable for clothing, towels and electronics in protective cases; the front pocket is for items that can tolerate splash. Not intended for towing or for prolonged submersion.
Quality Inspection Standards
Every production run is checked at IQC, IPQC and OQC. The suite covers load testing to 1,500 cycles, zipper fatigue to 3,000 cycles, tensile and bonding strength on welded seams and attachment patches, salt-spray on metal hardware, abrasion, colour fastness and colour difference against the approved sample, and full water immersion on finished bags. Because the main zip is airtight, bags also go through our customer inspection procedure — unboxing, vacuum extraction, 24-hour static rest and air-leak determination — which identifies pinhole weld faults and zip seating issues before shipment. Third-party inspection by SGS or QIMA can be arranged at the buyer's cost.
Product Highlights
Airtight main zip with a fold-over collar as secondary protection, IPX7 on the main compartment. Welded seams and welded attachment patches with no stitch holes through the main wall. Three carry modes, with detachable shoulder straps and a fixed padded back panel. Daisy chain, D-rings and end-cap loops for clipping gear on deck. Cross straps that double as compression. MOQ 300 with single-colour or two-tone Pantone matching.
Printing and Logo
Screen printing suits one- to three-colour marks on TPU and resists abrasion and UV. Heat transfer handles multi-colour artwork. Welded TPU patches give a tonal raised mark consistent with the welded construction. Woven labels and embroidery are placed on the shoulder straps, shoulder pad and handle wrap only — never through the welded waterproof body. Artwork is required as vector files; a digital placement proof is returned before sampling.
OEM / ODM Capability
Sealock has manufactured waterproof bags for over 20 years, with factories in Guangdong, China and Ho Chi Minh City, Vietnam — the second site giving brands a non-China origin option where tariff exposure matters. We hold ISO 9001, BSCI, SMETA, Higg, GRS and SCAN, and have produced for marine and outdoor brands including Helly Hansen, Musto, West Marine and attwood.
This product combines both of our core processes: the waterproof body is high-frequency welded, while the shoulder straps, padded wraps and shoulder pad are sewn — and sewn construction is an equally mature in-house capability, not a subcontracted add-on. Most demanding requirements can be met, from a colourway change to a full redesign with a different capacity, closure or harness; complex development with new patterns adds time to the first sample cycle, which is worth planning for early.
Related Products
- TPU Waterproof Adventure Duffel Bag with Airtight Zipper
- TPU420D Waterproof Duffel Bag
- 38L Waterproof Dry Backpack for Kayak
- Waterproof Backpack for Travel Dry Bag
- Waterproof Dry Bag with Viewing Window — 2L to 80L, 500D PVC
FAQ
What is the minimum order quantity?
300 pieces per colour. Two-tone colourways count as one colour for MOQ purposes.
What does it cost?
Price depends on quantity, fabric, closure type, strap option and logo method. Send your specification to info@sealock.com.hk and we will quote within one working day.
Can we add our own logo?
Yes. Screen print, heat transfer and welded patches on the body; woven labels and embroidery on the straps and pads. Pantone matching on body, webbing and hardware colour is available.
Is the whole bag waterproof?
The main compartment is rated IPX7 with the airtight zip closed. The front pocket is splash-proof only and should not hold phones or documents.
Do I need to fold the collar?
No. The airtight zip seals the main compartment on its own. Folding the collar and clipping the handles over it adds protection against grit and standing water, which keeps the zip working smoothly for longer.
Will it float?
With the main zip closed and some trapped air, the bag will float for a period, but it is not a flotation device and should not be relied on as one.
Is it comfortable as a backpack?
The detachable shoulder straps are padded and clip onto a fixed padded back panel, suitable for walks of up to an hour or two with a moderate load. For long-distance hiking, a dedicated dry backpack with a hip belt is the better choice.
How do I look after the airtight zip?
Rinse off salt and sand after use, lubricate the zip teeth with a silicone-based stick every few trips, and never force it closed over grit. Store the bag with the zip open.
Can the shoulder straps be removed?
Yes. The backpack shoulder straps and the single shoulder strap both unclip, leaving the bag as a hand-carried duffel. The padded back panel is fixed to the body and stays in place.
What is the lead time?
Samples in 7–15 days. Production is 30–35 days after sample approval, from either the China or the Vietnam factory.
Request a Quote
Send your target quantity, colourway, carry-mode requirements and logo artwork to info@sealock.com.hk. We will return a quotation with sample lead time and recommended construction.